Method for fractionation of hydrocarbons

ABSTRACT

A process for separation of a liquid phase from a gas phase and a process for production of a hydrocarbon product employing such a separation as well as a fractionation section and a hydrocracker section for carrying out such processes. The separation process includes: directing a feed for separation to a feed inlet of a means of separation; directing a stripping medium to a stripping medium inlet of the means of separation; withdrawing a liquid product stream from a means of separation; withdrawing a gaseous fraction comprising the stripping medium from the means of separation; directing the stripping medium fraction or the gaseous fraction as a recycled stripping medium; pressurizing at least an amount of the recycled stripping medium and directing it as the stripping medium, wherein the stripping medium comprises at least 80% vol/vol % of gases from the group comprising N2, H2, He, Ar, Ne and CO2.

The present invention relates to the field of separation of hydrocarbonsand similar compounds by fractionation according to boiling point.

Separation of hydrocarbons and similar compounds by boiling point is acommon process in refineries and petrochemical processes. An increasedspecificity of the separation is often related to an increased yield orvalue of products.

Separation in a distillation column may be aided by reboiling of theheavy fraction, but this may be problematic for some feeds, which mayreact or decompose in the fractionation column, with yield loss and/orprecipitation and fouling of the equipment as consequences.

It is common to aid the separation by the addition of a strippingmedium, which enhances fractionation by lowering the partial pressure ofthe light components, which thus are more completely vaporized.

Typical stripping media are steam and hydrogen, but also fuel gas(methane, ethane and possibly propane) have been used. The strippingmedium will be separated with the lightest fraction and will typicallyend up as a waste stream, which is either combusted or releasedotherwise, and thus the use of a stripping medium may be costly.Therefore, the amount of stripping medium is moderated in considerationof the balance between additional purity or yield and the cost ofstripping medium. In addition, the stripping medium may be problematicin itself; steam may cause corrosion challenges or water condensationand some stripping media such as fuel gas may be dissolved in theproduct with the consequence of requiring a later clean-up of product.

The present invention seeks to improve the separation quality, withoutincreasing the cost of using a stripping medium during separation ofhydrocarbons by recycling of the stripping medium.

According to the present disclosure a non-condensing stripping mediumsuch as elemental nitrogen, methane or fuel gas is directed to contact ahydrocarbon mixture.

A method for separation may either be a fractionation process havingseveral outlets based on boiling point or it may be a simpler strippingprocess wherein only a single liquid outlet and a single gaseous outletare used.

A stripping medium shall in the following be construed as a lightcomponent directed to support a separation process.

Fractionation shall in the following be construed as a separationprocess of molecules according to boiling point, by distillation.

In the following the abbreviation wt/wt % shall be used to signifyweight percentage.

In the following the abbreviation vol/vol % shall be used to signifyvolume percentage for a gas.

Where pressures for means of separation such as distillation columns arediscussed in the following, the pressure is in accordance with theterminology of the art determined at the top of the column, i.e.typically the lowest pressure of the column.

A broad aspect of the present disclosure relates to a process forseparation of a hydrocarbonaceous liquid phase from a gas phasecomprising the steps of

-   -   a. directing a feed for separation to a feed inlet of a means of        separation    -   b. directing a stripping medium to a stripping medium inlet of        said means of separation    -   c. withdrawing a liquid product stream from a means of        separation    -   d. withdrawing a gaseous fraction comprising said stripping        medium from said means of separation    -   e. optionally cooling and separating said gaseous fraction in a        light product fraction and a stripping medium fraction    -   f. directing said stripping medium fraction or said gaseous        fraction as a recycled stripping medium    -   g. pressurizing at least an amount of said recycled stripping        medium and directing it as said stripping medium of step b with        the associated benefit of a process with recycle of stripping        medium allowing an increased volume of stripping medium, such as        at least 2 wt/wt %, 3 wt/wt % or 4 wt/wt % relative to the feed        for separation, at little or no increase in cost, or        alternatively a decrease of cost, while maintaining the same        amount of stripping medium and separation quality.

In a further aspect the process further comprises the steps of

-   -   h. directing said liquid product stream to a secondary means of        separation,    -   i. directing an amount of said stripping medium as a side stream        stripping medium to said secondary means of separation,    -   j. withdrawing a gaseous side stream fraction comprising said        side stream stripping medium from said secondary means of        separation,    -   k. directing said gaseous side stream fraction to the means of        separation and    -   l. withdrawing a liquid product fraction from said secondary        means of separation,        wherein said stripping medium comprises at least 80% vol/vol %        or 90 vol/vol % of gases from the group comprising N₂, H₂, He,        Ar, Ne and CO₂, with the associated benefit of providing a        process with recycle of side stripper stripping medium allowing        an increased volume of side stripper stripping medium, at little        or no increase in cost.

In a further aspect the operating pressure of said means of separationis from atmospheric pressure to 2 barg and said pressurizing of saidrecycled stripping medium involves increasing the pressure by 0.1 bar to2 bar, with the associated benefit of designing to process for such amoderate pressurization of the recycled stripping medium being a lowcapital and operation cost of the means of pressurization, andspecifically allowing the option of using a blower technology.

In a further aspect the operating pressure of said means of separationis from 0 mbar absolute to 200 or 500 mbar absolute and saidpressurizing of said recycled stripping medium involves increasing thepressure by between 5 mbar and 50 or 200 mbar, with the associatedbenefit of designing to process for such a moderate pressurization ofthe recycled stripping medium being a low capital and operation cost ofthe means of pressurization, and specifically allowing the option ofusing a blower technology.

In a further aspect less than 5 wt/wt % of said feed is non-condensableat the boiling point of said stripping medium, with the associatedbenefit of the stripping medium being simple to separate from thelightest part of feed prior to recycle.

In a further aspect at least 95 wt/wt % or 99 wt/wt % of said feed iswithdrawn from said means of separation in liquid form, with theassociated benefit of the combination of non-condensable strippingmedium and liquid product fractions being that an energy efficientseparation of stripping medium from products is possible, allowingrecycle of the stripping medium without excessive cooling or heating.

In a further aspect at least 90 vol/vol % of said stripping medium isnon-condensable at 20° C. and 1 atmosphere, such as gases from the groupcomprising N₂, H₂, He, Ar, Ne, CO₂, CH₄ and C₂H₆, with the associatedbenefit of these constituents being gaseous at relevant processconditions, and typically being compatible with product specificationsand being compatible with material specifications, including corrosionstability. Specifically, H₂, CO₂, CH₄ and C₂H₆ are available in theprocess, N₂ is available at low cost and easily separated from otherstreams, noble gases such as He, Ar and Ne are highly inert, CH₄ andC₂H₆ may be taken as side streams from relevant process steps and CO₂—ora mixture of CO₂ and N₂ may be obtained from the dried flue gas of afired heater.

In a further aspect the feed has an initial boiling point of at least100° C., 200° C. or 300° C., with the associated benefit of a processfor separation of heavy feed being especially suitable for beingoperated with recycle of stripping medium as the separation of strippingmedium will be simpler, the positive effect on separation higher and thebenefits from avoiding thermal cracking in the absence of reboiling of afraction of the feed will also be higher.

In a further aspect the 95% boiling point of said feed is 400° C., 500°C. or 600° C. with the associated benefit of a process being able toseparate a heavy feed while avoiding a very heavy bottoms product.

In a further aspect the ratio between the amount of stripping medium andthe amount of feed directed to the means of separation is from 10 NL/kg,40 NL/kg or 100 NL/kg to 200 NL/kg, 400 NL/kg or 1000 NL/kg, with theassociated benefit of providing a balance between a low cost at lowratios and a high separation efficiency at higher ratios.

In a further aspect wherein the stripping medium comprises at least anamount of a gas originating from the gas source supplying blanketing gasfor product tanks, with the associated benefit of provision ofblanketing gas already being enabled on the premises of a refinery, andthe requirements to e.g. inertness of blanketing gas being similar tothe requirements for a stripper gas.

In a further aspect from 1%, 2% or 5% to 10% of said recycled strippingmedium is withdrawn as a purge with the associated benefit of such apurge removing oxygen and other undesired impurities from the process,such that the level of impurities is kept below critical limits.

In a further aspect said recycled stripping medium is heated by heatexchange, with the associated benefit of such heating being an increasedefficiency of separation of dissolved light components.

A further aspect of the present disclosure relates to a process forproduction of a product boiling in the diesel range comprising the stepsof

-   -   a. directing a feed comprising at least 50 wt/wt % hydrocarbons        boiling above 350° C. to contact a material catalytically active        in hydrocracking under hydrocracking conditions selected for        converting from 20 wt/wt % to 80 wt/wt % of the hydrocarbons        boiling above 350° C. to products boiling below 350° C.,        providing a hydrocracked product    -   b. directing said hydrocracked product as a feed for separation,        optionally after gas/liquid separation in one or more steps, to        a process of fractionation employing a recycled stripping        medium,    -   c. withdrawing a fraction of hydrocracked product boiling in the        diesel range        with the associated benefit of such a process providing a highly        effective separation of diesel from heavy distillate, thus        allowing an increased yield of valuable product boiling in the        diesel range.

A further aspect of the present disclosure relates to a fractionationsection comprising a means of separation having a feed inlet, a means ofseparation stripping medium inlet, one or more product outlets and avapor outlet, and a means of pressurization having an inlet and anoutlet characterized in said vapor outlet being in fluid communicationwith the inlet of said means of pressurization, and said outlet of saidmeans of pressurization being in fluid communication with said means ofseparation stripping medium inlet.

with the associated benefit of such a fractionation section being ableto operate with recycle of the stripping medium, and thus highlyefficient in separation at a moderate operational cost, in comparisonwith a fractionation section not recycling the stripping medium.

In a further aspect the fractionation section further comprises a sidecolumn, having a side column feed inlet, a side column stripping mediuminlet, a side column vapor outlet and a side column liquid outlet,wherein said side column stripping medium inlet is in fluidcommunication with the outlet of said means of pressurization, with theassociated benefit of such a fractionation section being well suited forthe side columns operating with a high amount of stripping medium,resulting in an increased separation efficiency.

In a further aspect the fractionation section, further comprises abottoms stripper having a bottoms stripper stripping medium inlet, astripper vapor outlet, a bottoms stream inlet and a stripped bottomsoutlet, and where said means of separation further has a bottoms outlet,and wherein said bottoms stream inlet is configured for being in fluidcommunication with said bottoms outlet, optionally via a means ofheating, wherein said bottoms stripper stripping medium inlet isconfigured for being in fluid communication with said outlet of saidmeans of pressurization optionally via a means of heating, and whereinsaid stripper vapor outlet is in fluid communication with said means ofseparation stripping medium inlet, with the associated benefit of such afractionation section being suited for minimizing the amount of purgenecessary from a process producing HPNA by increasing the separationefficiency of the bottoms stripper.

A further aspect of the present disclosure relates to a hydrocrackersection comprising a hydrocracking reactor having an inlet and an outletand a fractionation section comprising a means of separation having afeed inlet, a make up stripping medium inlet, one or more productoutlets and a vapor outlet, and a means of pressurization having aninlet and an outlet characterized in said hydrocracker section beingconfigured for directing an amount of product from the hydrocrackingreactor outlet to the means of separation feed inlet vapor outlet beingin fluid communication with the inlet of said means of pressurization,and said outlet of said means of pressurization being in fluidcommunication with said stripping medium inlet, with the associatedbenefit of such a process providing a highly effective separation ofdiesel from heavy distillate, thus allowing an increased yield ofvaluable product boiling in the diesel range.

In refinery operation fractional distillation or fractionation, i.e.processes separation according to boiling point, is a key unitoperation. The crude oil comprises many chemical components, having awide boiling range, e.g. from 40° C. to more than 600° C. Fractionaldistillation processes are carried out on the crude oil, to provide thetypical fuel fractions e.g. naphtha, kerosene, diesel, lubricant andbunker fuel. Fractional distillation is also carried out on a wide rangeof intermediate products, e.g. where an intermediate fraction with ahomogeneous boiling range has been treated in a chemical process, suchthat products with different boiling point are produced. Typically, thechemical processes involve hydroprocessing, in which crude oil reactswith hydrogen, in the presence of catalysts.

Hydroprocessing may be in the form of hydrotreatment, which maintain thestructure of the crude oil hydrocarbons, but release light components,such as NH₃, H₂O and H₂S. Hydroprocessing may also be in the form ofhydrocracking, in which the structure of hydrocarbons is broken down toform smaller compounds.

The separation of products is typically carried out in a fractionaldistillation process, where a means of separation, typically adistillation column with multiple trays and multiple outlets is used.The temperature decreases from the inlet towards the top of thedistillation column, and from each outlet a fraction can be withdrawn,which comprises the condensed product. In a side column, this stream isdivided in a liquid stream and a gaseous stream. The gaseous stream isreturned to the main column. From such a column each outlet will providea stream boiling in a defined range, but the separation will beimperfect with overlapping fractions.

One reason for the imperfect separation is that an amount of lightproducts is dissolved in the liquid. Therefore, the main column and theside columns are often equipped with stripping medium streams, which canaid the separation, by the principle of decreasing the vapor pressure ofthe light products above the liquid.

Separation, especially in the case of simple gas/liquid separations, maybe carried out at the process pressure, which typically is elevated.This is convenient especially where the products are to be furthertreated at elevated pressure. However, since the boiling point of acomponent is dependent on the pressure, separation may be more efficientat low pressure. The separation is often carried out slightly aboveatmospheric pressure, e.g. at 0.1 barg to 3 barg (where barg means bargauge, e.g. pressure relative to atmospheric pressure), which involvesthe simplest equipment. Such separation is called atmosphericseparation. Even more efficient separation may be carried out at reducedpressure, e.g. 0 bar to 0.2 or 0.5 bar (absolute pressure), which mayalso have the benefit of avoiding excessive heating to temperatureswhere the components are unstable. Such separation is called vacuumseparation.

Stripping medium may beneficially be used to aid separation at allpressures, but the physical equipment to be used will differ, dependingon the pressure of operation.

To increase the separation efficiency, especially for the highestboiling constituents, the heaviest bottom fraction may also be reboiled,i.e. directed to be heated, such that at least an amount of the bottomfraction is evaporated, and returned to the column. This improvesseparation, but during reboiling the high temperatures may lead tothermal cracking, and thus reduce the total recuperation of hydrocarbonsand cause fouling of equipment leading to more frequent interruption ofoperation to clean the affected items.

The economy of a separation process depends on the balance betweenoperational expense for the process and the value of the products. Theproducts must adhere to standards, and thus a poor separation must becompensated by a restrictive limitation of boiling point. However, anincreased yield of more valuable product may be obtained by improvedseparation, and therefore it may be beneficial to accept increasedoperational expense to gain product value. The operational expensesrelated to separation may also be balanced against the operationalexpense of downstream processes.

Use of stripping medium is one example of added operational expensewhich provides a net economic benefit. The typical stripping medium issteam, and the production, and thus production and use of steam isrelated to a consumption of energy, which has a cost. However, when aseparation is aided by steam as stripping medium, the separationefficiency may be increased, such that each fraction comprises a highamount of components well suited for the fraction. After stripping, thetemperature will be low and steam is collected as liquid water, whichmust be heated and vaporized to be used as stripping medium again.

If the amount of stripping steam is increased, the separation efficiencymay be further increased, but the balance between cost and gain willreach a maximum at some level, beyond which the cost of steam andequipment size exceeds the value of improved separation. In addition,the use of steam increases the requirements to corrosion resistance ofmaterials and causes a need for removal of water from the products.

Now, according to the present disclosure, it is proposed to use astripping medium being gaseous at standard temperature, such as N2, andfurthermore to recirculate the stripping medium around the separationprocess, which is not possible when the stripping medium is steam, sincethe used steam is condensed as liquid water. The use of a gaseousstripping medium has the benefit that the separation of stripping mediumfrom the light feed fraction being uncomplicated, especially if theboiling points of the stripping medium and the light feed fraction areremote from each other. The use of recirculation has the benefit thatthe cost of providing stripping medium is reduced, since only a minoramount released to the surroundings or dissolved in the separated feedfractions must be replenished. As the cost of stripping medium isreduced, the balance between the cost of stripping medium and the valueof separation efficiency will be shifted towards a higher separationefficiency, and thus less requirement for distancing the fractionationcut point from the classification limits of products.

The requirements to the feed and the stripping medium for use in aprocess where the stripping medium is recycled include, as mentioned,that the boiling point is remote from that of the lightest feed, suchthat the product is at least 95 wt/wt % condensing, while the strippingmedium is non-condensing in the fractionation section, which typicallyincludes an overhead drum having a lower temperature than the column.The lowest temperature is typically in the overhead drum, whichtypically is 20-120° C. depending on environmental conditions. Thismeans that for atmospheric fractionation it is preferred that theproduct does not include significant amounts of fuel gas, e.g. methane,ethane and propane. For a vacuum fractionation, even butane and pentanemay be undesired in the product. The criterion that the stripping mediumis non-condensing allows at least N₂, H₂, He, Ar, Ne, CO₂, CH₄ and C₂H₆as stripping media. It is also beneficial that the stripping medium isinert and has a low solubility in the hydrocarbon products, to avoid aloss of stripping medium and a product in accordance with thespecifications, which makes N₂ a preferred stripping medium. Anotherbenefit of N₂ is that it is typically available in refineries in pureform, for the purpose of blanketing storage tanks.

While the concept is described above as it relates to an atmosphericfractionator, a similar concept may also be used for vacuumfractionators. For a vacuum fractionator, specific considerations mustbe made. It is in general important that the equipment is airtight whenoperating under vacuum, but when a gaseous stripping medium isrecirculated, this becomes even more important, as leaks may introduceoxygen, which with recirculation may reach dangerous levels. Therefore,purge, scavenging with a solid or a liquid scavenger or selectiveconversion of oxygen may preferentially be included when stripping mediais recirculated with a vacuum fractionator.

The present disclosure is also relevant for hydroprocessing, especiallya hydrocracking process, in which a heavy feedstock is hydrocracked anddirected to a fractionation process employing a recycled strippingmedium. A hydrocracking process is especially well suited for beingcombined with such a fractionation process, as a cascade of vapor/liquidseparators will ensure that the feed for separation contains little orno non-condensing product, such that purification of the strippingliquid is avoided or minimized. Hydrotreatment processes involving heavyproducts may also benefit from such a configuration, especially if theamount of light products is minimal.

FIGURES

FIG. 1 shows a fractionation section according to the presentdisclosure.

FIG. 2 shows a fractionation section according to the prior art.

FIG. 3 shows a hydrocracking section, with a fractionation sectionaccording to the present disclosure.

FIG. 1 shows an aspect of the present disclosure. Two hydrocrackedfossil feeds for separation 102 and 104 (or optionally a single combinedstream) are directed to a feed inlet of a means of separation 106. Anamount of stripping medium 108 is directed to a stripping medium inletof the means of separation 106. Liquid product fractions 112, 122 arewithdrawn from a number of positions of said means of separation 106,and each of these fractions are purified in secondary means ofseparation such as side column strippers 114, 124, where a furtheramount of stripping medium is added as side stripper stripping medium116, 126, stripped liquid fractions 118, 128 are withdrawn and the sidestripper gaseous fractions 120, 130 are directed to the means ofseparation 106. At the top of the means of separation the lightestfraction 142 is withdrawn, and optionally separated in a three phaseseparator 144, from which the liquid hydrocarbon fraction 145 may bedirected to the column as recycle 146 and/or withdrawn as product 148.The gaseous fraction 150 from the three phase separator is directed to ameans of pressurization such as a blower or a compressor 152, typicallyafter but optionally before being heated e.g. in heat exchanger 154, andrecycled as stripping medium 158, in combination with a limited amountof make-up stripping medium 160. From the bottom of the means ofseparation a bottoms product 162 is withdrawn.

In a further aspect a purge of stripping medium may be withdrawn withthe objective of avoiding concentrating impurities. The impurities maygaseous product hydrocarbons or oxygen from equipment leaks. The purgestream may be directed to an absorbent or a reactor for removing theimpurities. Removal of oxygen may be carried out by catalytic oxidationof hydrocarbons or hydrogen or liquid or solid scavenging and thegaseous products may be collected e.g. in an amine wash. Gaseoushydrocarbons may be directed to other means of separation.

FIG. 2 shows an aspect of the prior art. Two hydrocracked fossil feedsfor separation 202 and 204 are directed to a feed inlet of a means ofseparation 206. An amount of stripping medium, typically steam 208 isdirected to a stripping medium inlet of the means of separation 206.Liquid product fractions 212, 222 are withdrawn from a number ofpositions of said means of separation 206, and each of these fractionsare purified in secondary means of separation such as side columnstrippers 214, 224, where a further amount of stripping medium is addedas side stripper stripping medium 216, 226, stripped liquid fractions218, 228 are withdrawn and the side stripper gaseous fractions streams220, 230 are directed to the means of separation 206. At the top of themeans of separation the lightest fraction 242 is withdrawn, and aftercooling separated in a three phase separator to a gas fraction 264, aliquid hydrocarbon fraction 245 and a water fraction 268 in three phaseseparator 244. The liquid fraction 266 from the three phase separator244 may be directed to the column as recycle 246 and/or withdrawn asproduct 248. From the bottom of the means of separation a bottomsproduct 262 is withdrawn.

FIG. 3 shows an aspect of the present disclosure. A feed 372 is directedto a hydrocracking reactor 374 comprising a hydrocracking catalyst. Thehydrocracked product 376 is directed to a cascade of separators, 378,380, 382, 384 from which a cold product stream 386 and a hot productstream 388 are withdrawn and directed to a stripper 390. From thestripper vapor 391 and liquid product stream 392 are withdrawn. Theliquid product stream 392 is preheated and separated in flash vessel 394into a vapor product stream 304 and a liquid product 396. The liquidproduct is heated in heater 398. The heated liquid product 302 and thevapor product stream 304 are directed to a means of separation 306. Anamount of stripping medium 308 is directed to a stripping medium inletof the means of separation 306. Liquid product fractions 312, 322 arewithdrawn from a number of positions of said means of separation 306,and each of these fractions are purified in secondary means ofseparation such as side column strippers 314, 324, where a furtheramount of stripping medium is added as side stripper stripping medium316, 326, stripped liquid fractions 318, 328 is withdrawn and the sidestripper vapor gaseous fractions streams 320, 330 are directed to themeans of separation 306. At the top of the means of separation thelightest fraction 342 is withdrawn, and optionally separated in a threephase separator 344, from which the liquid hydrocarbon fraction 345 maybe directed to the column as recycle 346 and/or withdrawn as product348. The gaseous fraction 350 from the three phase separator is directedto a means of pressurization such as a blower or a compressor 352optionally before or after being heated 354, and recycled as strippingmedium 358, in combination with a limited amount of make-up strippingmedium 360. The make up stripping medium 360 may optionally be suppliedas a side stream of the blanket gas used in the storage tanks ofproducts. From the bottom of the means of separation a bottoms product362 is withdrawn.

EXAMPLES

The efficiency of separation according to the present disclosure and theprior art has been evaluated by studying the fractionation of theproducts of a hydrocracking process.

Example 1

In Example 1 the product of a hydrocracking process is directed to afractionation according to the present disclosure, as described in FIG.1, in which the stripping medium is N₂, and the total N₂:HC ratio intothe column and side columns is 1.7 mol/kg, and N₂ is recycled to be usedas stripping medium. The performance of the fractionation process isshown in Table 1. According to this example, 0.35% of the N₂ must beadded as make up gas due to N₂ being dissolved in the products. If a 2%purge of stripping N₂ was included, it would be required to add 2.35% asmake up N₂.

In Table 1 it is seen that all products fulfill the specifications forthe respective product types.

Example 2

In Example 2 the product of a hydrocracking process is directed to afractionation according to the prior art, as described in FIG. 2, inwhich the stripping medium is steam and the total H₂O:HC ratio into thecolumn and side columns is 0.7 mol/kg. H₂O is condensed at the outlet ofthe column, but cannot be recycled to be used as stripping medium,unless it is heated and vaporized in a steam drum.

The performance of the fractionation process is shown in Table 2, whichalso show the product fractions. The product qualities are similar tothose of Example 1.

The product yields of Example 1 and Example 2 are compared in Table 3.It is seen that an extra yield of valuable products like kerosene anddiesel is obtained and the yield of less valuable products like naphthaand unconverted oil (UCO) is reduced.

In addition to the increased yield, the use of recycled nitrogen asstripping medium in Example 1 will furthermore have the benefit ofhaving a lower operational expense, compared to the required amount ofsteam in Example 2.

The examples thus document that recycled nitrogen provides an improvedseparation and thus a reduced yield loss while also being a costeffective alternative to steam.

TABLE 1 Stream 102 104 108 148 128 118 162 Total Mass Rate kg/hr 28,298296,520 15,785 36,189 115,238 43,912 128,261 Flash Point Temperature °C. 7 21 1 36 77 173 (Closed Cup) Total RVP psi 2 1 18 0 0 40(APINAPHTHA) Cetane Index 16 64 12 45 60 59 TBP at 760 mm Hg ° C. IBP 6887 64 107 138 318  5 wt/wt % 92 115 84 129 247 367 10 wt/wt % 100 131 92139 278 378 30 wt/wt % 117 238 105 175 320 405 50 wt/wt % 134 337 113211 337 430 70 wt/wt % 174 406 119 248 353 462 90 wt/wt % 246 476 126289 375 510 95 wt/wt % 285 505 129 303 383 539 EBP 428 575 137 326 404583

TABLE 2 208/216/ Stream 202 204 226 248 228 218 262 Total Mass Ratekg/hr 28,298 296,520 4,250 36,501 113,668 42,325 131,134 Flash Point °C. 7 21 0.9 36.0 81.2 170.3 Temperature (Closed Cup) Total RVP Psi 2 12.2 0.1 0.0 0.9 (APINAPHTHA) Cetane Index 16 64 12 44 60 59 TBP at 760mm Hg ° C. IBP 68 87 65 107 147 311  5 wt/wt % 92 115 84 129 241 360 10wt/wt % 100 131 92 139 271 375 30 wt/wt % 117 238 105 174 316 403 50wt/wt % 134 337 113 210 335 429 70 wt/wt % 174 406 119 246 352 461 90wt/wt % 246 476 126 288 375 509 95 wt/wt % 285 505 129 302 383 538 EBP428 575 136 327 405 583

TABLE 3 Prior art Invention Difference Naphtha (kg/hr)  36,501  36,189−0.9% Kerosene (kg/hr) 113,668 115,238 1.4% Diesel (kg/hr)  42,325 43,912 3.8% UCO (kg/hr) 131,134 128,261 −2.2%

1. A process for separation of a hydrocarbonaceous liquid phase from agas phase comprising the steps of a. directing a feed for separation toa feed inlet of a means of separation, b. directing a stripping mediumto a stripping medium inlet of said means of separation, c. withdrawinga liquid product stream from said means of separation, d. withdrawing agaseous fraction comprising said stripping medium from said means ofseparation, e. optionally cooling and separating said gaseous fractionin a light product fraction and a stripping medium fraction, f.directing said stripping medium fraction or said gaseous fraction as arecycled stripping medium, g. pressurizing at least an amount of saidrecycled stripping medium and directing it as said stripping medium ofstep b, wherein said stripping medium comprises at least 80% vol/vol %of gases from the group comprising N₂, Hz, He, Ar, Ne and CO₂.
 2. Theprocess of claim 1 further comprising the steps of h. directing saidliquid product stream to a secondary means of separation, i. directingan amount of said stripping medium as a side stream stripping medium tosaid secondary means of separation, j. withdrawing a gaseous side streamfraction comprising said side stream stripping medium from saidsecondary means of separation, k. directing said gaseous side streamfraction to the means of separation and l. withdrawing a liquid productfraction from said secondary means of separation.
 3. The processaccording to claim 1 wherein the operating pressure of said means ofseparation is from atmospheric pressure to 3 barg and said pressurizingof said recycled stripping medium involves increasing the pressure by0.1 bar to 2 bar.
 4. The process according to claim 1 wherein theoperating pressure of said means of separation is from 0 bar absolute to500 mbar absolute and said pressurizing of said recycled strippingmedium involves increasing the pressure by between 5 mbar and 200 mbar.5. The process according to claim 1 wherein less than 5 wt/wt % of saidfeed is non-condensable at the boiling point of said stripping medium.6. The process according to claim 1 wherein at least 95 wt/wt % of saidfeed is withdrawn from said means of separation in liquid form.
 7. Theprocess according to claim 1 wherein the feed has an initial boilingpoint of at least 100° C.
 8. The process according to claim 1 whereinthe 95 wt/wt % boiling point of said feed is at least 400° C.
 9. Theprocess according to claim 1 wherein the ratio between the amount ofstripping medium and the amount of feed directed to the means ofseparation is from 10 NL/kg to 500 NL/kg.
 10. The process according toclaim 1 wherein from 1% to 10% of said recycled stripping medium iswithdrawn as a purge.
 11. A process for production of a low boilingproduct, said process comprising the steps of x. directing a feedcomprising at least 50 wt/wt % hydrocarbons boiling above an uppertarget boiling point, to contact a material catalytically active inhydrocracking under hydrocracking conditions selected for convertingfrom 30 wt/wt % to 100 wt/wt % of the hydrocarbons boiling above theupper target boiling point to products boiling below the upper targetboiling point, providing a hydrocracked product y. directing saidhydrocracked product as a feed for separation, optionally aftergas/liquid separation in one or more steps, to a process offractionation employing a recycled stripping medium, z. withdrawing afraction of hydrocracked product boiling in the low boiling productrange.
 12. A fractionation section comprising a means of separationhaving a feed inlet, a means of separation stripping medium inlet, oneor more product outlets and a vapor outlet, and a means ofpressurization having an inlet and an outlet characterized in said vaporoutlet being in fluid communication with the inlet of said means ofpressurization, and said outlet of said means of pressurization being influid communication with said means of separation stripping mediuminlet.
 13. The fractionation section according to claim 12 furthercomprising a side column, having a side column feed inlet, a side columnstripping medium inlet, a side column vapor outlet and a side columnliquid outlet, wherein said side column stripping medium inlet is influid communication with the outlet of said means of pressurization. 14.The fractionation section according to claim 12, further comprising abottoms stripper having a bottoms stripper stripping medium inlet, astripper vapor outlet, a bottoms stream inlet and a stripped bottomsoutlet, and where said means of separation further has a bottoms outlet,and wherein said bottoms stream inlet is configured for being in fluidcommunication with said bottoms outlet, optionally via a means ofheating, wherein said bottoms stripper stripping medium inlet isconfigured for being in fluid communication with said outlet of saidmeans of pressurization optionally via a means of heating, and whereinsaid stripper vapor outlet is in fluid communication with said means ofseparation stripping medium inlet.
 15. A hydrocracker section comprisinga hydrocracking reactor having an inlet and an outlet and afractionation section comprising a means of separation having a feedinlet, a make up stripping medium inlet, one or more product outlets anda vapor outlet, and a means of pressurization having an inlet and anoutlet characterized in said hydrocracker section being configured fordirecting an amount of product from the hydrocracking reactor outlet tothe means of separation feed inlet, the vapor outlet being in fluidcommunication with the inlet of said means of pressurization, and saidoutlet of said means of pressurization being in fluid communication withsaid stripping medium inlet.